The present invention relates generally to an ignition voltage analyzer and more particularly to an interface for interconnecting or coupling the pick-up and output of an ignition voltage analyzer.
It is well known today that the conditions and performance of an automotive ignition system can be determined and evaluated by analysis of the ignition signal waveforms and particularly the secondary ignition coil waveform. The primary and secondary coil voltages are very rapid, time varying signals.
Although satisfactory in a limited sense, much of the presently available automotive test equipment is functionally inadequate for complete and thorough analysis of the waveforms. For example, electromagnetic and electrostatic cathode ray tubes are extensively used for display of the ignition wave signals. Unfortunately, the amplitude variations are often too rapid for tracking by the oscilloscope. Thus, the displayed voltage is incomplete as well as inaccurate.
This difficulty or shortcoming is particularly significant with respect to the peak amplitude of the secondary coil voltage, i.e., the firing voltage. The rapid collapse of the primary coil magnetic field induces a substantially spontaneous high voltage in the secondary coil. The rapid rise of the secondary coil voltage substantially prohibits the measurement of peak voltage, although a significant factor in evaluating engine performance.
The rapid signal variations and inability of the presently known equipment to accurately track also substantially prohibit use or utilization of a digital processor. That is, the ignition voltage signals cannot be "held" a sufficient period of time for analog-to-digital conversion, i.e., digitization.
Additionally, various ignition system components, such as the ignition coil, cannot be tested directly with the presently known equipment. The component must be removed from the system for indirect analysis. This operation requires the time-consuming, frequently destructive task of disconnection and, more significantly, prohibits performance measurements under true operating conditions.